The combined workforce of Japan's top 100 construction companies as of the end of March shrank 5.5 percent from a year earlier to 202,378, marking its sixth straight year of decline, a private research institute said Thursday. The downward trend reflects difficulties facing general contractors, who have made payroll reductions a pillar of their restructuring measures, according to Teikoku Databank.

The combined workforce of the top 100 contractors was down by more than 40,000 from its peak at the end of March 1994.

Of the 100 leading construction firms, 93 firms cut their workforces in the year to March. Kajima Corp. cut 963 workers, followed by Sato Kogyo Co., which laid off 936, and Kumagai Gumi Co., with 877 dismissals.

Each of these general contractors has reduced its workforce by more than 2,000 since the 1994 peak.

A number of general contractors are still struggling and looking to streamline further, which may prompt an industry realignment, a Teikoku Databank researcher said.

As a result, more jobs are likely to be lost, the researcher said.